The European Union's top diplomat and Iran's foreign minister say nuclear talks between six world powers and Tehran did not seal a deal.
The EU's Catherine Ashton and Iranian Foreign Minister Mohammad Javad Zarif say progress was made over three days of efforts.
But they said early Sunday that further rounds are needed to agree on initial limits on Iran's nuclear program in exchange for some easing of sanctions on its economy.
World powers will reconvene at the political directors' level on Nov. 20 in Geneva for more talks.
Tehran says it does not want atomic arms but has said it is ready for concessions if sanctions are lifted.
